GM Service Manual Online
For 1990-2009 cars only

Refer to
Object Number: 501684  Size: FS
LH HTD ST/BCM, DR LK, PWR MIR and CLSTR/BCM Fuses, HEADLAMP and RETAINED ACCSRY PWR Relays, and RETAINED ACCSRY PWR Circuit Breaker
PCM BCM/CLSTR, PWR MIR, CLSTR/BCM Fuses, RETAINED ACCSRY PWR CIRCUIT Breaker, HEADLAMP and RETAINED ACCSRY PWR Relays
SIR Handling Caution
G203 (2 of 3)
G201 (1 of 2)
Data Link Communications Components
Data Link Communications Circuit Description
Handling ESD Sensitive Parts Notice
.

Circuit Description

The powertrain control module (PCM) receives rough road information from the EBCM/EBTCM on the serial data circuit. The PCM uses the rough road information to enhance the misfire diagnostic by distinguishing the crankshaft speed variations caused by driving on rough road surfaces from the variations caused by true misfires. The EBCM/EBTCM transmits the rough road information based on inputs from the wheel speed sensors. If the EBCM/EBTCM detects a condition which will not allow proper identification rough road situations while a misfire condition is being detected by the PCM, DTC P1380 will be set.

Conditions for Running the DTC

    •  The engine load is less than 87.5 percent .
    •  The engine speed is less than 5000 RPM.
    •  The vehicle speed is more than 10 mph.
    •  A misfire DTC is occurring and requesting MIL illumination.

Conditions for Setting the DTC

The PCM has detected a EBCM/EBTCM rough road sensing error.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

DTC P1380 set indicates that the ABS system has detected a malfunction which will not allow the EBCM/EBTCM to transmit the correct rough road data to the PCM. The Diagnostic System Check - ABS in Antilock Brake Systems should be used to diagnose this condition.

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System test?

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Go to Diagnostic System Check - ABS in Antilock Brake Systems

Go to Powertrain On Board Diagnostic (OBD) System Check